DESCRIPTION (Applicant's abstract): This application is a revision of a proposal submitted in response to Program Announcement PA-93-093 for Exploratory/Development Grants (R21) for Psychosocial Treatment Research. We propose to develop a new psychotherapy of depression based upon self-discrepancy theory, an integrative approach to the role of the self-system in depression and other disorders. The theory provides a unique conceptual basis for developing a treatment for depression that focuses more directly on the self-system than currently available treatments. The new treatment is intended for depressed patients whose current episodes of depression are characterized by high levels of self-discrepancy. We propose a two-phase program of development for the new treatment model, which we call Self-System Therapy (SST). During Phase I, the treatment model will be expanded and refined, and a treatment manual and therapy adherence/therapist competence measure will be constructed. In Phase II, the model, manual, and adherence/competence measure will be evaluated in a clinical trial comparing SST with Standard cognitive-behavioral therapy in depressed outpatients manifesting high levels of self-discrepancy. This project is ideally suited for the Program Announcement. Self-System Therapy will be the first psychotherapy for depression developed to address a specific source of vulnerability to the onset and maintenance of depression. This project exemplifies how basic science should enhance treatment development, by progressing logically from theory to laboratory studies to clinical applications.